511045555561 has 4 divisors (see below), whose sum is σ = 513467572624. Its totient is φ = 508623538500.

The previous prime is 511045555487. The next prime is 511045555567. The reversal of 511045555561 is 165555540115.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-511045555561 is a prime.

It is a super-2 number, since 2×511045555561² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (511045555567) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1211008215 + ... + 1211008636.

It is an arithmetic number, because the mean of its divisors is an integer number (128366893156).

Almost surely, 2^511045555561 is an apocalyptic number.

It is an amenable number.

511045555561 is a deficient number, since it is larger than the sum of its proper divisors (2422017063).

511045555561 is a wasteful number, since it uses less digits than its factorization.

511045555561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2422017062.

The product of its (nonzero) digits is 375000, while the sum is 43.

The spelling of 511045555561 in words is "five hundred eleven billion, forty-five million, five hundred fifty-five thousand, five hundred sixty-one".